The use of and development of communications has grown nearly exponentially in recent years. The growth is fueled by larger networks with more reliable protocols and better communications hardware available to service providers and consumers. One embodiment of an important service is pseudowire. A pseudowire is an emulation of a native service over a packet switched network (PSN). The native service may be low-rate or high-rate time domain multiplexing (TDM), synchronous optical network (SONET)/SDH, asynchronous transfer mode (ATM), frame relay, or other similar service while the PSN may be Ethernet, multi-protocol label switching (MPLS), or other Internet protocol (IP).
One critical issue in implementing TDM pseudowire is clock recovery. In native TDM networks, the physical layer carries highly accurate timing information along with the TDM data. However, when emulating TDM over PSNs, this physical layer clock may be absent. TDM timing standards may be exacting and conformance with such standards may require innovative mechanisms to adaptively reproduce the TDM timing or original clock signal.